SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6778297982119c9f5e3b6ddd8846db5c05c11fd36bde6aa2d3ea8aba167ff711' 
  AND token = 'LJ379lPiG3vsw9gB4z4R8ReGvdZhTgbXTU+NZOzjbVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}